Single-Layer Touch Sensor

ABSTRACT

In one embodiment, a touch sensor includes a first electrode and a second electrode. At least a portion of the second electrode is interdigitated with the first electrode. The first electrode includes a base portion, a digit and an extent. The digit includes a first end and a second end, connects to the base portion at the first end, and extends from the base portion in a first direction along a first axis. The extent connects to the digit at the second end and extends from the digit along a second axis that is substantially perpendicular to the first axis.

TECHNICAL FIELD

This disclosure generally relates to touch sensors.

BACKGROUND

A touch sensor may detect the presence and location of a touch or theproximity of an object (such as a user's finger or a stylus) within atouch-sensitive area of the touch sensor overlaid on a display screen,for example. In a touch-sensitive-display application, the touch sensormay enable a user to interact directly with what is displayed on thescreen, rather than indirectly with a mouse or touch pad. A touch sensormay be attached to or provided as part of a desktop computer, laptopcomputer, tablet computer, personal digital assistant (PDA), smartphone,satellite navigation device, portable media player, portable gameconsole, kiosk computer, point-of-sale device, or other suitable device.A control panel on a household or other appliance may include a touchsensor.

There are a number of different types of touch sensors, such as (forexample) resistive touch screens, surface acoustic wave touch screens,and capacitive touch screens. Herein, reference to a touch sensor mayencompass a touch screen, and vice versa, where appropriate. When anobject touches or comes within proximity of the surface of thecapacitive touch screen, a change in capacitance may occur within thetouch screen at the location of the touch or proximity. A touch-sensorcontroller may process the change in capacitance to determine itsposition on the touch screen.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example touch sensor with an example touch-sensorcontroller.

FIG. 2A illustrates an example pattern for an example single-layer touchsensor.

FIG. 2B illustrates another example pattern for an example single-layertouch sensor.

FIG. 3A illustrates cross-sectional views of the single-layer touchsensor of FIGS. 2A-B with example electric fields.

FIG. 3B illustrates other cross-sectional views of the single-layertouch sensor of FIGS. 2A-B with example electric fields.

FIG. 4A illustrates another example pattern for an example single-layertouch sensor.

FIG. 4B illustrates another example pattern for an example single-layertouch sensor.

DESCRIPTION OF EXAMPLE EMBODIMENTS

FIG. 1 illustrates an example touch sensor 10 with an exampletouch-sensor controller 12. Touch sensor 10 and touch-sensor controller12 may detect the presence and location of a touch or the proximity ofan object within a touch-sensitive area of touch sensor 10. Herein,reference to a touch sensor may encompass both the touch sensor and itstouch-sensor controller, where appropriate. Similarly, reference to atouch-sensor controller may encompass both the touch-sensor controllerand its touch sensor, where appropriate. Touch sensor 10 may include oneor more touch-sensitive areas, where appropriate. Touch sensor 10 mayinclude an array of drive and sense electrodes (or an array ofelectrodes of a single type) disposed on one or more substrates, whichmay be made of a dielectric material. Herein, reference to a touchsensor may encompass both the electrodes of the touch sensor and thesubstrate(s) that they are disposed on, where appropriate.Alternatively, where appropriate, reference to a touch sensor mayencompass the electrodes of the touch sensor, but not the substrate(s)that they are disposed on.

An electrode (whether a ground electrode, a guard electrode, a driveelectrode, or a sense electrode) may be an area of conductive materialforming a shape, such as for example a disc, square, rectangle, thinline, other suitable shape, or suitable combination of these. One ormore cuts in one or more layers of conductive material may (at least inpart) create the shape of an electrode, and the area of the shape may(at least in part) be bounded by those cuts. In particular embodiments,the conductive material of an electrode may occupy approximately 100% ofthe area of its shape. As an example and not by way of limitation, anelectrode may be made of indium tin oxide (ITO) and the ITO of theelectrode may occupy approximately 100% of the area of its shape(sometimes referred to as 100% fill), where appropriate. In particularembodiments, the conductive material of an electrode may occupysubstantially less than 100% of the area of its shape. As an example andnot by way of limitation, an electrode may be made of fine lines ofmetal or other conductive material (FLM), such as for example copper,silver, carbon, or a copper- or silver- or carbon-based material, andthe fine lines of conductive material may occupy approximately 5% of thearea of its shape in a hatched, mesh, or other suitable pattern. Herein,reference to ELM encompasses such material, where appropriate. Althoughthis disclosure describes or illustrates particular electrodes made ofparticular conductive material forming particular shapes with particularfill percentages having particular patterns, this disclosurecontemplates any suitable electrodes made of any suitable conductivematerial forming any suitable shapes with any suitable fill percentageshaving any suitable patterns.

Where appropriate, the shapes of the electrodes (or other elements) of atouch sensor may constitute in whole or in part one or moremacro-features of the touch sensor. One or more characteristics of theimplementation of those shapes (such as, for example, the conductivematerials, fills, or patterns within the shapes) may constitute in wholeor in part one or more micro-features of the touch sensor. One or moremacro-features of a touch sensor may determine one or morecharacteristics of its functionality, and one or more micro-features ofthe touch sensor may determine one or more optical features of the touchsensor, such as transmittance, refraction, or reflection.

A mechanical stack may contain the substrate (or multiple substrates)and the conductive material forming the drive or sense electrodes oftouch sensor 10. As an example and not by way of limitation, themechanical stack may include a first layer of optically clear adhesive(OCA) beneath a cover panel. The cover panel may be clear and made of aresilient material suitable for repeated touching, such as for exampleglass, polycarbonate, or poly(methyl methacrylate) (PUMA). Thisdisclosure contemplates any suitable cover panel made of any suitablematerial. The first layer of OCA may be disposed between the cover paneland the substrate with the conductive material forming the drive orsense electrodes. The mechanical stack may also include a second layerof OCA and a dielectric layer (which may be made of PET or anothersuitable material, similar to the substrate with the conductive materialforming the drive or sense electrodes). As an alternative, whereappropriate, a thin coating of a dielectric material may be appliedinstead of the second layer of OCA and the dielectric layer. The secondlayer of OCA may be disposed between the substrate with the conductivematerial making up the drive or sense electrodes and the dielectriclayer, and the dielectric layer may be disposed between the second layerof OCA and an air gap to a display of a device including touch sensor 10and touch-sensor controller 12. As an example only and not by way oflimitation, the cover panel may have a thickness of approximately 1 mm;the first layer of OCA may have a thickness of approximately 0.05 mm;the substrate with the conductive material forming the drive or senseelectrodes may have a thickness of approximately 0.05 mm; the secondlayer of OCA may have a thickness of approximately 0.05 mm; and thedielectric layer may have a thickness of approximately 0.05 mm. Althoughthis disclosure describes a particular mechanical stack with aparticular number of particular layers made of particular materials andhaving particular thicknesses, this disclosure contemplates any suitablemechanical stack with any suitable number of any suitable layers made ofany suitable materials and having any suitable thicknesses. As anexample and not by way of limitation, in particular embodiments, a layerof adhesive or dielectric may replace the dielectric layer, second layerof OCA, and air gap described above, with there being no air gap to thedisplay.

One or more portions of the substrate of touch sensor 10 may be made ofpolyethylene terephthalate (PET) or another suitable material. Thisdisclosure contemplates any suitable substrate with any suitableportions made of any suitable material. In particular embodiments, thedrive or sense electrodes in touch sensor 10 may be made of ITO in wholeor in part. In particular embodiments, the drive or sense electrodes intouch sensor 10 may be made of fine lines of metal or other suitableconductive material. As an example and not by way of limitation, one ormore portions of the conductive material may be copper or copper-basedand have a thickness of approximately 5 μm or less and a width ofapproximately 10 μm or less. As another example, one or more portions ofthe conductive material may be silver or silver-based and similarly havea thickness of approximately 5 μm or less and a width of approximately10 μm or less. This disclosure contemplates any suitable electrodes madeof any suitable material.

Touch sensor 10 may implement a capacitive form of touch sensing. In amutual-capacitance implementation, touch sensor 110 may include an arrayof drive and sense electrodes forming an array of capacitive nodes. Adrive electrode and a sense electrode may form a capacitive node. Thedrive and sense electrodes forming the capacitive node may come neareach other, but not make electrical contact with each other. Instead,the drive and sense electrodes may be capacitively coupled to each otheracross a space between them. A pulsed or alternating voltage applied tothe drive electrode (by touch-sensor controller 12) may induce a chargeon the sense electrode, and the amount of charge induced may besusceptible to external influence (such as a touch or the proximity ofan object). When an object touches or comes within proximity of thecapacitive node, a change in capacitance may occur at the capacitivenode and touch-sensor controller 12 may measure the change incapacitance. By measuring changes in capacitance throughout the array,touch-sensor controller 12 may determine the position of the touch orproximity within the touch-sensitive area(s) of touch sensor 10.

In a self-capacitance implementation, touch sensor 10 may include anarray of electrodes of a single type that may each form a capacitivenode. When an object touches or comes within proximity of the capacitivenode, a change in self-capacitance may occur at the capacitive node andtouch-sensor controller 12 may measure the change in capacitance, forexample, as a change in the amount of charge needed to raise the voltageat the capacitive node by a pre-determined amount. As with amutual-capacitance implementation, by measuring changes in capacitancethroughout the array, touch-sensor controller 12 may determine theposition of the touch or proximity within the touch-sensitive area(s) oftouch sensor 10. This disclosure contemplates any suitable form ofcapacitive touch sensing, where appropriate.

In particular embodiments, one or more drive electrodes may togetherform a drive electrode line running horizontally or vertically or in anysuitable orientation. Similarly, one or more sense electrodes maytogether form a sense electrode line running horizontally or verticallyor in any suitable orientation. Additionally, one or more groundelectrodes may together form a ground electrode line runninghorizontally or vertically or in any suitable orientation. In particularembodiments, drive electrode lines may run substantially perpendicularto sense electrode lines. In particular embodiments, drive electrodelines may run substantially parallel to sense electrode lines. Herein,reference to a drive electrode line may encompass one or more driveelectrodes making up the drive electrode line, and vice versa, whereappropriate. Similarly, reference to a sense electrode line mayencompass one or more sense electrodes making up the sense electrodeline, and vice versa, where appropriate. Additionally, reference to aground electrode line may encompass one or more ground electrodes makingup the ground electrode line, and vice versa, where appropriate. Inparticular embodiments, any electrode may be configured as a drive,sense, or ground electrode and the configuration of any electrode may bechanged during operation of touch sensor 10. In particular embodiments,configuration of electrodes may be controlled by touch-sensor controller12.

Touch sensor 10 may have drive and sense electrodes disposed in apattern on one side of a single substrate. In such a configuration, apair of drive and sense electrodes capacitively coupled to each otheracross a space between them may form a capacitive node. For aself-capacitance implementation, electrodes of only a single type may hedisposed in a pattern on a single substrate. In addition or as analternative to having drive and sense electrodes disposed in a patternon one side of a single substrate, touch sensor 10 may have driveelectrodes disposed in a pattern on one side of a substrate and senseelectrodes disposed in a pattern on another side of the substrate.Moreover, touch sensor 10 may have drive electrodes disposed in apattern on one side of one substrate and sense electrodes disposed in apattern on one side of another substrate. In such configurations, anintersection of a drive electrode and a sense electrode may form acapacitive node. Such an intersection may be a location where the driveelectrode and the sense electrode “cross” or come nearest each other intheir respective planes. The drive and sense electrodes do not makeelectrical contact with each other instead they are capacitively coupledto each other across a dielectric at the intersection. Although thisdisclosure describes particular configurations of particular electrodesforming particular nodes, this disclosure contemplates any suitableconfiguration of any suitable electrodes forming any suitable nodes.Moreover, this disclosure contemplates any suitable electrodes disposedon any suitable number of any suitable substrates in any suitablepatterns.

In particular embodiments, touch sensor 10 may determine the position ofan object (such as a stylus or a user's finger or hand) that makesphysical contact with a touch-sensitive area of touch sensor 10. Inaddition or as an alternative, in particular embodiments, touch sensor10 may determine the position of an object that comes within proximityof touch sensor 10 without necessarily contacting touch sensor 10. Inparticular embodiments, an object may come within proximity of touchsensor 10 when it is located some distance above a surface of touchsensor 10; when it hovers in a particular position above a surface oftouch sensor 10; when it makes a motion (such as for example a swipingmotion or an air gesture) above a surface of touch sensor 10; or anysuitable combination of the above. In particular embodiments,determining the position of an object that comes within proximity oftouch sensor 10 without making physical contact may be referred to asdetermining the proximity of an object. In particular embodiments,determining the proximity of an object may comprise determining theposition of an object's projection onto touch sensor 10 when the objectis located some distance above a plane of touch sensor 10. Theprojection of an object onto touch sensor 10 may be made along an axisthat is substantially orthogonal to a plane of touch sensor 10. Inparticular embodiments, the position of an object's projection ontotouch sensor 10 may be referred to as the position or the location of anobject. As an example and not by Way of limitation, touch sensor 10 maydetermine the position of an object when the object is located above thesurface of touch sensor 10 and within a distance of approximately 20 mmof the surface of touch sensor 10. Although this disclosure describes orillustrates particular touch sensors that may determine a position ofphysical contact of an object, a proximity of an object, or acombination of the two, this disclosure contemplates any suitable touchsensor 10 suitably configured to determine a position of physicalcontact of an object, a proximity of an object, or any suitablecombination of one or more of the above.

As described above, a change in capacitance at a capacitive node oftouch sensor 10 may indicate a touch or proximity input at the positionof the capacitive node. Touch-sensor controller 12 may detect andprocess the change in capacitance to determine the presence and locationof the touch or proximity input. Touch-sensor controller 12 may thencommunicate information about the touch or proximity input to one ormore other components (such one or more central processing units (CPUs))of a device that includes touch sensor 10 and touch-sensor controller12, which may respond to the touch or proximity input by initiating afunction of the device (or an application running on the device).Although this disclosure describes a particular touch-sensor controllerhaving particular functionality with respect to a particular device anda particular touch sensor, this disclosure contemplates any suitabletouch-sensor controller having any suitable functionality with respectto any suitable device and any suitable touch sensor.

Touch-sensor controller 12 may be one or more integrated circuits (ICs),such as for example general-purpose microprocessors, microcontrollers,programmable logic devices or arrays, application-specific ICs (ASICs).In particular embodiments, touch-sensor controller 12 comprises analogcircuitry, digital logic, and digital non-volatile memory. In particularembodiments, touch-sensor controller 12 is disposed on a flexibleprinted circuit (FPC) bonded to the substrate of touch sensor 10, asdescribed below, The FPC may be active or passive, where appropriate. Inparticular embodiments, multiple touch-sensor controllers 12 aredisposed on the FPC. Touch-sensor controller 12 may include a processorunit, a drive unit, a sense unit, and a storage unit. The drive unit maysupply drive signals to the drive electrodes of touch sensor 10. Thesense unit may sense charge at the capacitive nodes of touch sensor 10and provide measurement signals to the processor unit representingcapacitances at the capacitive nodes. The processor unit may control thesupply of drive signals to the drive electrodes by the drive unit andprocess measurement signals from the sense unit to detect and processthe presence and location of a touch or proximity input within thetouch-sensitive area(s) of touch sensor 10. The processor unit may alsotrack changes in the position of a touch or proximity input within thetouch-sensitive area(s) of touch sensor 10. The storage unit may storeprogramming for execution by the processor unit, including programmingfor controlling the drive unit to supply drive signals to the driveelectrodes, programming for processing measurement signals from thesense unit, and other suitable programming, where appropriate. Althoughthis disclosure describes a particular touch-sensor controller having aparticular implementation with particular components, this disclosurecontemplates any suitable touch-sensor controller having any suitableimplementation with any suitable components.

Tracks 14 of conductive material disposed on the substrate of touchsensor 10 may couple the drive or sense electrodes of touch sensor 10 toconnection pads 16, also disposed on the substrate of touch sensor 10.As described below, connection pads 16 facilitate coupling of tracks 14to touch-sensor controller 12. Tracks 14 may extend into or around (e.g.at the edges of) the touch-sensitive area(s) of touch sensor 10.Particular tracks 14 may provide drive connections for couplingtouch-sensor controller 12 to drive electrodes of touch sensor 10,through which the drive unit of touch-sensor controller 12 may supplydrive signals to the drive electrodes. Other tracks 14 may provide senseconnections for coupling touch-sensor controller 12 to sense electrodesof touch sensor 10, through which the sense unit of touch-sensorcontroller 12 may sense charge at the capacitive nodes of touch sensor10. Tracks 14 may be made of fine lines of metal or other conductivematerial. As an example and not by way of limitation, the conductivematerial of tracks 14 may be copper or copper-based and have a width ofapproximately 100 μm or less. As another example, the conductivematerial of tracks 14 may be silver or silver-based and have a width ofapproximately 100 μm or less. In particular embodiments, tracks 14 maybe made of ITO in whole or in part in addition or as an alternative tofine lines of metal or other conductive material. Although thisdisclosure describes particular tracks made of particular materials withparticular widths, this disclosure contemplates any suitable tracks madeof any suitable materials with any suitable widths. In addition totracks 14, touch sensor 10 may include one or more ground electrodelines terminating at a ground connector (which may be a connection pad16) at an edge of the substrate of touch sensor 10 (similar to tracks14).

Connection pads 16 may be located along one or more edges of thesubstrate, outside the touch-sensitive area(s) of touch sensor 10. Asdescribed above, touch-sensor controller 12 may be on an FPC. Connectionpads 16 may be made of the same material as tracks 14 and may be bondedto the FPC using an anisotropic conductive film (ACF). Connection 18 mayinclude conductive lines on the FPC coupling touch-sensor controller 12to connection pads 16, in turn coupling touch-sensor controller 12 totracks 14 and to the drive or sense electrodes of touch sensor 10. Inanother embodiment, connection pads 16 may be connected to anelectro-mechanical connector such as a zero insertion forcewire-to-board connector); in this embodiment, connection 18 may not needto include an FPC. This disclosure contemplates any suitable connection18 between touch-sensor controller 12 and touch sensor 10.

FIG. 2A (which is not necessarily shown to scale) illustrates an examplesingle-layer touch sensor for use in the example system of FIG. 1. Inthe example of FIG. 2A, touch sensor 10 includes tracking areas 202A-Band a touch-sensitive area. Herein, reference to a touch sensor mayencompass one or more of a tracking area and a touch-sensitive area,where appropriate. The touch-sensitive area of touch sensor 10 includesan array of sense electrode lines 208A-B and an array of drive electrodelines 210A-C. Herein, reference to a touch-sensitive area of a touchsensor may encompass one or more of a drive electrode line and one ormore of a sense electrode line, where appropriate. In the example ofFIG. 2A, drive electrode lines 210[A/B/C] extend substantially inparallel along a longitudinal axis of touch sensor 10. In contrast,sense electrode lines 208A-B extend substantially in parallel along alatitudinal axis of touch sensor 10. Each sense electrode line 208[A/B]further includes a sense electrode while each drive electrode line210[A/B/C] further includes one or more drive electrodes. Herein,reference to an electrode line may encompass one or more of anelectrode, where appropriate. If an electrode line includes only oneelectrode (such as sense electrode line 208[A/B] as described above),reference to the electrode line may encompass the electrode, andvice-versa, where appropriate. In the example of FIG. 2A, driveelectrodes 210[A-C][1-2] are disposed serially along the longitudinalaxis of touch sensor 10. Although this disclosure describes andillustrates a touch-sensitive area of touch sensor 10 as including bothdrive and sense electrodes, this disclosure contemplates thetouch-sensitive area of touch sensor 10 including electrodes of a singletype, where appropriate. Furthermore although this disclosure describesand illustrates one or more of a particular electrode together forming aparticular electrode line that extends in a particular orientation, thisdisclosure contemplates one or more of any suitable electrode formingany suitable electrode line that extends in any suitable orientation. Asan example and not by way of limitation, sense electrode lines mayextend substantially parallel to drive electrode lines, as describedabove. As another example and not by way of limitation, each electrodeline 208[A/B] may include a drive electrode and each electrode line210[A/B/C] may include one or more sense electrodes. In the example ofFIG. 2A, tracking areas 202A-B include tracks 14 that facilitatecoupling of sense electrodes 208A-B and drive electrodes 210[A-C][1-2]to a touch-sensor controller 12, as described above. Although thisdisclosure describes and illustrates tracks 14 of tracking areas 202A-Bextending continuously in a particular orientation, tracks 14 oftracking areas 202A-B may extend in any suitable orientations, whereappropriate.

An electrode (whether a drive electrode or a sense electrode) may be anarea of conductive material forming a shape, such as for example a disc,square, rectangle, other suitable shape, or suitable combination ofthese. In particular embodiments, an electrode may include an array ofrepeated conductive materials. Each conductive material of the array ofrepeated conductive materials has the same pattern. As an example ofFIG. 2A, sense electrode 208A includes a column array of repeatedconductive materials disposed serially along the latitudinal axis.Furthermore the repeated conductive materials are disposed such that thenext conductive material mirrors the last conductive material along thelatitudinal axis. Each repeated conductive material of sense electrode208A includes a base portion and two digits. As an example of FIG. 2A,an example repeated conductive material includes a base portion 212 andtwo digits 214A-B. Each digit 214[A/B] connects to base portion 212 at afirst end and extends from base portion 212 in a first direction alongthe longitudinal axis. The base portion 212 extends substantiallyparallel along the latitudinal axis. As another example of FIG. 2A,sense electrode 208A includes a plurality of base portions that are eachconnected in series to at least one adjacent mirrored base portion.Although this disclosure describes and illustrates a repeated conductivematerial of a particular electrode of touch sensor 10 as having a baseportion 212 and two digits 214A-B connected in a particular manner, thisdisclosure contemplates any suitable repeated conductive material of anysuitable electrode of touch sensor 10 as having any suitable number ofany suitable base portions and any suitable number of any suitabledigits connected in any suitable manner. Furthermore although thisdisclosure describes and illustrates a particular electrode of touchsensor 10 having a particular pattern, this disclosure contemplates anysuitable electrode of touch sensor 10 having any suitable pattern (orshape) or any suitable combination of any suitable patterns (or shapes).As an example of FIG. 2A and not by way of limitation, drive electrode210C1 includes digits 216A-C that extend substantially perpendicularlyfrom a base portion of drive electrode 210C1.

Each of the drive electrodes may include a plurality of digits thatextend along the longitudinal axis in a particular direction from a baseportion. Corresponding sense electrode may include a plurality of digitsthat extend along the longitudinal axis at least in an oppositedirection from a base portion. Particular digits of the drive electrodemay be adjacent to a digit of the corresponding sense electrode formingcapacitive coupling edges separated by a gap. As such, the digits of thedrive and sense electrodes may be interdigitated (or interleaved) toincrease the number of capacitive coupling edges around one or moredrive electrodes and a corresponding sense electrode. As an example ofFIG. 2A and not by way of limitation, digits 216A-C of drive electrode210C1 may be interdigitated with digits 214A-B of corresponding senseelectrode 208A. Capacitive coupling between drive electrode 210C1 andcorresponding sense electrode 208A may be determined at least by gap 220and edges of digits 214A-B and 216A-C. Although this disclosuredescribes and illustrates a particular arrangement of electrodes fortouch sensor 10, this disclosure contemplates any suitable arrangementof electrodes for touch sensor 10.

FIG. 2B (which is not necessarily shown to scale) illustrates anotherexample single-layer touch sensor for use in the example system ofFIG. 1. In the example of FIG. 2B, an example repeated conductivematerial of sense electrode 208A further includes extents 218A-Bdisposed substantially in parallel to base portion 212 of the repeatedconductive material. Each extent 218[A/B] connects to a second end ofthe corresponding digit 214[A/B] and comprises extensions along thelatitudinal axis in first and second directions. Accordingly, the shapesof digits 216A-C of corresponding drive electrode 210C1 may change toaccommodate the extents 218A-B. As an example and not by way oflimitation, the shapes of digits 216A-C may change to preserveconsistency of the width of gap 220 between each digit 216A-C and itscorresponding sense electrode 208A, as illustrated by FIG. 2B. Inparticular embodiments, extents 218A-B may increase capacitive couplingof sense electrode 208A with one or more adjacent drive electrodes. Asan example of FIG. 2B (and illustrated more clearly in FIGS. 3A-B) andnot by way of limitation, extents 218A-B may improve capacitive couplingbetween sense electrode 208A and drive electrode 210C1 by substantiallyincreasing the electric field around the edges of extents 218A-B. As aresult of the increase, the strength of the electric field between senseelectrode 208A and drive electrode 210C1 as located around extent 218Amay be substantially similar to the strength of the electric fieldbetween sense electrode 208A and drive electrode 210B1 as located aroundbase portion 212. In particular embodiments, the increase in theelectric field may improve the detection of any movement of any objectthat comes within proximity of extents 218A-B of touch sensor 10.Although this disclosure describes and illustrates particular electrodeas having particular pattern that substantially enhances a capacitivecoupling of the particular electrode with particular adjacent electrodein a particular way, this disclosure contemplates any suitable electrodehaving any suitable pattern that substantially enhances any capacitivecoupling of the particular electrode with one or more of an adjacentelectrode in any suitable manner.

FIG. 3A (which is not necessarily shown to scale) illustratescross-sectional views 204A-B of the single-layer touch sensor of FIGS.2A-B with example electric fields 300A-B. In the example of FIG. 3A,cross-sectional views 204A-B illustrate and describe electric fields300A-B of sense electrodes 208A-B of FIG. 2A while cross-sectional view204B illustrates and describes electric fields 300A-B of senseelectrodes 208A-B of FIG. 2B. In comparison with cross-sectional view204A, electric fields 300A-B of cross-sectional view 204B includesadditional electric-field lines, The additional electric-field lines maybe provided at least by the extents in each repeated conductive materialof sense electrodes 208A-B, as described above. The additionalelectric-field lines may enhance the strength of the correspondingelectric fields 300A-B. As another example of cross-sectional view 204B,electric field 300A extending between sense electrode 208A and driveelectrode 210A1 may at least be substantially balanced with the electricfield extending between sense electrode 208A and drive electrode 210B1.Similarly, electric field 300B extending between sense electrode 208Band drive electrode 210A2 may at least be substantially balanced withthe electric field extending between sense electrode 208B and driveelectrode 210B2. Although this disclosure illustrates and describesparticular cross-sectional views of particular touch sensor withparticular electric fields between particular electrodes of particulartouch sensor, this disclosure contemplates any suitable cross-sectionalviews of any suitable touch sensor with any suitable electric fieldsbetween any suitable electrodes of the touch sensor.

FIG. 3B (which is not necessarily shown to scale) illustrates othercross-sectional views 206A-B of the single-layer touch sensor of FIGS.2A-B with example electric fields 302A-B. In the example of FIG. 3B,cross-sectional views 206A-B illustrate and describe electric fieldsextending between base portion 304A of sense electrode 208A and driveelectrodes 210A1 and 210B1. Similarly, cross-sectional views 206A-Billustrate and describe electric fields extending between base portion3049 of sense electrode 208B and drive electrodes 210A2 and 210B2.Furthermore, cross-sectional view 206B illustrates and describes newelectric field 302A extending between extent 306A (of sense electrode208A) and drive electrode 210A1. Similarly, cross-sectional view 206Billustrates and describes new electric field 302B extending betweenextent 3069 (of sense electrode 208B) and drive electrode 210A2.Electric fields 302A-B may be caused at least by extents 306A-B, asdescribed above. Although this disclosure illustrates and describesparticular cross-sectional views of particular touch sensor withparticular electric fields extending between particular electrodes ofthe touch sensor, this disclosure contemplates any suitablecross-sectional views of any suitable touch sensor with any suitableelectric fields extending between any suitable electrodes of the touchsensor.

FIG. 4A (which is not necessarily shown to scale) illustrates anotherexample single-layer touch sensor for use in the example system ofFIG. 1. In the example of FIG. 4A, touch sensor 10 includes atouch-sensitive area comprising sense electrode 402 and drive electrodes404A-E. Furthermore sense electrode 402 includes a column array ofrepeated conductive material disposed serially in a serpentine patternalong a latitudinal axis of touch sensor 10. Furthermore the repeatedconductive materials are disposed such that the next conductive materialmirrors the last conductive material along a longitudinal axis of thetouch sensor 10. Each repeated conductive material of sense electrode402 includes a base portion and a digit. As an example of FIG. 4A, anexample repeated conductive material includes base portion 408 and digit406. Base portion 408 extends diagonally to the latitudinal axis. Digit406 connects to base portion 408 at a first end and extendssubstantially obliquely from (or to) base portion 408 without beingparallel to base portion 408. As another example of FIG. 4A, senseelectrode 402 includes a plurality of base portions that are eachconnected in series to at least one adjacent mirrored base portion. Eachdigit of sense electrode 402 interdigitated (or interleaved) with one ormore adjacent digits of drive electrodes 404A-E along the latitudinalaxis of touch sensor 10. Although this disclosure describes andillustrates a repeated conductive material of a particular electrode oftouch sensor 10 as having a base portion 408 and a digit 406 connectedin a particular manner, this disclosure contemplates any suitablerepeated conductive material of any suitable electrode of touch sensor10 as having any suitable number of any suitable base portions and anysuitable number of any suitable digits connected in any suitable manner.Furthermore although this disclosure describes and illustrates aparticular electrode of touch sensor 10 having a particular pattern,this disclosure contemplates any suitable electrode of touch sensor 10having any suitable pattern (or shape) or any suitable combination ofany suitable patterns (or shapes).

FIG. 4B (which is not necessarily shown to scale) illustrates anotherexample single-layer touch sensor for use in the example system ofFIG. 1. In the example of FIG. 4B, each repeated conductive material ofsense electrode 402 includes extent 410 disposed substantially parallelto the latitudinal axis of touch sensor 10. Furthermore, extent 410connects to a second end of the corresponding digit 406 and comprisesextensions along the latitudinal axis in first and second directions. Incontrast to the example of FIG. 2B, shape of each corresponding adjacentand interleaved digit of drive electrodes 404A-E remains the same. Asanother example and not by way of limitation, each correspondingadjacent and interleaved digit of drive electrodes 404A-E may bemodified such that the width of the dielectric gap between each digit ofdrive electrodes 404A-E and its corresponding sense electrode 402 may beconsistent, as illustrated by FIG. 2B. Similar to the example of FIG.2B, extent 410 may improve capacitive coupling between sense electrode402 and drive electrode 404C by substantially increasing the electricfield around the edges of extent 410. In particular embodiments, theincrease in the electric field may improve the detection of any movementof any object that comes within proximity of extent 410. Although thisdisclosure describes and illustrates particular electrode as havingparticular pattern that substantially enhances a capacitive coupling ofthe particular electrode with particular adjacent electrode in aparticular way, this disclosure contemplates any suitable electrodehaving any suitable pattern that substantially enhances any capacitivecoupling of the particular electrode with one or more of an adjacentelectrode in any suitable manner.

Herein, reference to a computer-readable non-transitory storage mediumor media may include one or more semiconductor-based or other integratedcircuits (ICs) (such, as for example, a field-programmable gate array(FPGA) or an application-specific IC (ASIC)), hard disk drives (HDDs),hybrid hard drives (HHDs), optical discs, optical disc drives (ODDs),magneto-optical discs, magneto-optical drives, floppy diskettes, floppydisk drives (FDDs), magnetic tapes, solid-state drives (SSDs),RAM-drives, SECURE DIGITAL cards, SECURE DIGITAL drives, any othersuitable computer-readable non-transitory storage medium or media, orany suitable combination of two or more of these, where appropriate. Acomputer-readable non-transitory storage medium or media may bevolatile, non-volatile, or a combination of volatile and non-volatile,where appropriate.

Herein, “or” is inclusive and not exclusive, unless expressly indicatedotherwise or indicated otherwise by context. Therefore, herein, “A or B”means “A, B, or both,” unless expressly indicated otherwise or indicatedotherwise by context. Moreover, “and” is both joint and several, unlessexpressly indicated otherwise or indicated otherwise by context.Therefore, herein, “A and B” means “A and B, jointly or severally,”unless expressly indicated otherwise or indicated otherwise by context.

The scope of this disclosure encompasses all changes, substitutions,variations, alterations, and modifications to the example embodimentsdescribed or illustrated herein that a person having ordinary skill inthe art would comprehend. The scope of this disclosure is not limited tothe example embodiments described or illustrated herein. Moreover,although this disclosure describes and illustrates respectiveembodiments herein as including particular components, elements,functions, operations, or steps, any of these embodiments may includeany combination or permutation of any of the components, elements,functions, operations, or steps described or illustrated anywhere hereinthat a person having ordinary skill in the art would comprehend.Furthermore, reference in the appended claims to an apparatus or systemor a component of an apparatus or system being adapted to, arranged to,capable of configured to, enabled to, operable to, or operative toperform a particular function encompasses that apparatus, system,component, whether or not it or that particular function is activated,turned on, or unlocked, as long as that apparatus, system, or componentis so adapted, arranged, capable, configured, enabled, operable, oroperative.

What is claimed is:
 1. A touch sensor comprising: a first electrode thatcomprises: a base portion; a digit that comprises a first end and asecond end, connects to the base portion at the first end, and extendsfrom the base portion in a first direction along a first axis; and anextent that connects to the digit at the second end and extends from thedigit along a second axis that is substantially perpendicular to thefirst axis; and a second electrode that is at least partiallyinterdigitated with the first electrode.
 2. The touch sensor of claim 1,wherein the first electrode is a sense electrode and the secondelectrode is a drive electrode.
 3. The touch sensor of claim 1, wherein:the base portion extends parallel to the second axis; the digit extendssubstantially perpendicular to the base portion; and the extent issubstantially parallel to the base portion.
 4. The touch sensor of claim1, wherein: the base portion extends diagonally to the second axis; thedigit extends substantially obliquely to the base portion; and theextent is not substantially parallel to the base portion.
 5. The touchsensor of claim 1, wherein: the first electrode composes a firstelectrode line extending along the second axis; and the second electrodeis one of a plurality of second electrodes composing a second electrodeline extending along the first axis.
 6. The touch sensor of claim 5,wherein the first electrode: comprises a plurality of base portions thatare each connected to at least one adjacent base portion; and extendsalong the second axis in a serpentine pattern.
 7. The touch sensor ofclaim 1, wherein the first electrode comprises a plurality of digitsthat extend from the base portion in the first direction along the firstaxis.
 8. The touch sensor of claim 1, wherein: a first portion of theextent extends from the digit along the second axis in a firstdirection; and a second portion of the extent extends from the digitalong the second axis in a second direction that is opposite the firstdirection.
 9. The touch sensor of claim 1, wherein the first and secondelectrodes are each made of a mesh of fine lines of conductive material.10. The touch sensor of claim 1, wherein the first and second electrodesare each made of indium tin oxide (ITO).
 11. A device comprising: atouch sensor comprising: a first electrode that comprises: a baseportion; a digit that comprises a first end and a second end, connectsto the base portion at the first end, and extends from the base portionin a first direction along a first axis; and an extent that connects tothe digit at the second end and extends from the digit along a secondaxis that is substantially perpendicular to the first axis; and a secondelectrode that is at least partially interdigitated with the firstelectrode; and one or more computer-readable non-transitory storagemedia comprising logic that is configured when executed to control thetouch sensor.
 12. The device of claim 11, wherein the first electrode isa sense electrode and the second electrode is a drive electrode.
 13. Thedevice of claim 11, wherein: the base portion extends parallel to thesecond axis; the digit extends substantially perpendicular to the baseportion; and the extent is substantially parallel to the base portion.14. The device of claim 11, wherein: the base portion extends diagonallyto the second axis; the digit extends substantially obliquely to thebase portion; and the extent is not substantially parallel to the baseportion.
 15. The device of claim 11, wherein: the first electrodecomposes a first electrode line extending along the second axis; and thesecond electrode is one of a plurality of second electrodes composing asecond electrode line extending along the first axis.
 16. The device ofclaim 15, wherein the first electrode: comprises a plurality of baseportions that are each connected to at least one adjacent base portion;and extends along the second axis in a serpentine pattern.
 17. Thedevice of claim 11, wherein the first electrode comprises a plurality ofdigits that extend from the base portion in the first direction alongthe first axis.
 18. The device of claim 11, wherein: a first portion ofthe extent extends from the digit along the second axis in a firstdirection; and a second portion of the extent extends from the digitalong the second axis in a second direction that is opposite the firstdirection.
 19. The device of claim 11, wherein the first and secondelectrodes are each made of a mesh of fine lines of conductive material.20. The device of claim 11, wherein the first and second electrodes areeach made of indium tin oxide (ITO).